Brain iron in patients with Parkinson disease: MR visualization using gradient modification.

In patients with Parkinson disease, improved visualization of brain iron on a mid-field-strength magnet can be obtained with T2-weighted images and elimination of phase-encoding artifacts. A long echo delay time accentuates the loss of signal from brain iron. However, the long pulse sequence creates phase-encoding artifacts from CSF pulsations at the level of the basal ganglia. These artifacts are eliminated and resolving power increased with additional pulsing in the slice-selective and read gradients. Elimination of motion artifacts enhances visualization of brain iron in three ways: (1) extrapyramidal nuclei containing iron have better definition, (2) abnormalities are better identified, and (3) pseudolesions disappear. Our findings suggest there is significant improvement in the resolving power of brain iron on MR scans made with a mid-field-strength scanner when gradient modification is used.

Nuclear magnetic resonance (NMR): I. Imaging biochemical change.

Nuclear magnetic resonance (NMR) imaging of hydrogen in body water and fat is proving valuable in clinical investigation of the brain. An introduction to the technique and to the biological significance of the images is presented here. The 'multi-parameter' nature of these images is stressed, and the individual parameters described. NMR imaging may well be of value in investigating the pathology of organic and functional psychoses.

Nuclear magnetic resonance (NMR). II. Imaging in dementia.

Proton NMR imaging of the brain is rapidly becoming established as a useful investigative tool in medicine. This paper examines the usefulness of the NMR parameters--spin-lattice relaxation time (T1) and proton density (PD)--in differentiating groups of patients with senile dementia of Alzheimer type (SDAT) and multi-infarct dementia (MID) from each other, and from elderly controls. T1 values increase with severity of dementia. NMR parameters may also be of use in localising regions of brain damage.

[NMR imaging in dementia states. A diagnostic and quantitative study]. / NMR-imaging in Demenzzuständen. Eine diagnostische und quantitative studie.

Spin lattic relaxation times (T1) and proton density derived from proton nuclear magnetic resonance imaging data are measured in elderly patients with senile dementia of Alzheimer type (SDAT) and multi infarct dementia (MID) and the results compared with elderly controls. T1 values of the cerebral white matter are increased in the dementia groups and there is a statistical correlation with severity. Patients with SDAT have significantly differing proton density measures in cerebral white matter from those with MID. The potential value of these results are discussed together with the possible application to identify regional areas of damage.

Cognitive evaluation following NMR imaging of the brain.

Nuclear magnetic resonance imaging of the brain will soon be a standard neuroradiological investigation. Previous work has indicated that this is a safe procedure. Tests which measure various aspects of cognition were performed on volunteer subjects before and after (medium and short term) NMR brain imaging and indicate that deterioration did not occur.

Reactogenicity and immunogenicity of a surface-antigen-adsorbed influenza virus vaccine in children.

An influenza virus vaccine containing the purified surface haemagglutinin and neuraminidase antigens of A/Victoria/75 and B/Hong Kong/73 viruses adsorbed to an aluminium hydroxide gel was assessed for reactogenicity and immunogenicity in children aged 4 to 11 years, since there is no influenza virus vaccine available for this age group. Significant serum haemagglutination-inhibiting antibody responses to the A/Victoria/75 and B/Hong Kong/73 haemagglutinin antigens present in the vaccine were observed in 47% and 35%, respectively, of the children vaccinated, with a single dose. The vaccine induced no significant local or systemic reactions.